Hotspot - Local Redirect with WAN status displayed

Hello,
I am working with the WRT54GS, utilizing the hotspot feature predominantly with chillispot enabled. I need to find a way to allow the end user to know if the Data Source (ISP Connection) is up and functioning. Currently we have our initial redirect page remotely hosted and this is causing a problem as obviously, the end user simply gets 'page cannnot be displayed' or 'server cannot be found'. My coding experience is less than minimal and searching the www has left me with more questions than answers. My thought was of using a simple if/then statement to display the WAN interface Connectivity status. However, I am unsure of what the correct syntax would be when using the WRT54GS and DD-WRT .v23. So far the setup has been flawless; until I help someone place the WRT54GS on thier dynamic Data Line and the IP Changes or they have service interuption. As we provide this as a free service, the ability to tech support the end user is limited. Help with this concern would be greatly appreciated.